Understanding Filler Rheology: An In‑Depth Guide for Aesthetic Injectors

Written By Chance Wonder

The Importance of Rheology in Filler Selection

Rheology describes how fillers flow and deform under mechanical forces. In aesthetic practice, filler behavior depends on its elastic modulus (G′)—a measure of firmness—and cohesivity, or how well a filler holds together under compression (Sundaram et al., 2015; Trévidic et al., 2023). Selecting fillers based on these properties leads to safer, more predictable, and longer-lasting results (Choi, 2020; Park et al., 2021).

Core Rheological Properties

  • G′ (Elastic or Storage Modulus): Higher values (~200–300 Pa) resist deformation, ideal for structural areas such as the jawline and cheeks. Lower G′ (<150 Pa) is better for soft tissue areas like lips and tear troughs (RSC Advances, 2023; Trévidic et al., 2023).

  • Viscous Modulus (G″) & Tan δ: G″ represents energy lost to flow; tan δ (G″/G′) helps determine whether a filler behaves more like a gel or liquid in motion (Tang et al., 2020).

  • Cohesivity: Indicates resistance to compression. High cohesivity supports projection under tissue pressure; low cohesivity allows smooth integration in dynamic areas (Sundaram et al., 2015; Trévidic et al., 2023).

Recommended Rheology by Treatment Area

Jawline, Chin, and Nose

Requires high G′ and high cohesivity fillers.

  • Calcium Hydroxylapatite (CaHA, e.g., Radiesse®): High G′ and cohesive structure mimic bone support—ideal for the jawline and chin (Cohen & Biesman, 2021; Sundaram et al., 2015).

Midface (Cheeks and Zygoma)

Needs medium-to-high G′ and medium cohesivity to resist shear forces and maintain projection.

  • Hyaluronic Acid (HA): Juvéderm® Voluma XC and Restylane® Lyft have G′ values around 200–300 Pa and sustained lift (RSC Advances, 2023; McCarthy et al., 2024).

Nasolabial & Marionette Lines

Requires moderate G′ with balanced cohesivity for flexibility and integration.

  • Revanesse® Versa™: Offers a mid-range rheological profile—sufficient structure with natural tissue flexibility (Cohen & Biesman, 2021).

Lips & Tear Troughs

Prefer low G′ and low cohesivity for soft, moldable results.

  • Belotero® Balance, Juvéderm® Volbella, Restylane® Silk are commonly used due to their softness and ability to minimize swelling (Trévidic et al., 2023).

Temples & Superficial Planes

Use spreadable, low-viscosity gels to avoid visibility or nodules.

  • Hyperdiluted CaHA or low-cohesivity HA fillers offer gentle, supportive smoothing when used with cannulas (Trévidic et al., 2023).

Spotlight on Revanesse® Versa™

Revanesse Versa™ utilizes Thixofix™ cross-linking, yielding consistent rheology and a round HA particle structure. It offers mid-range G′ and cohesivity, making it ideal for:

  • Nasolabial folds

  • Marionette lines

  • Moderate cheek volume enhancement

Its lower hydrophilicity reduces post-procedure swelling. While excellent for dynamic lines, it is less suited for high-support areas such as the jawline or structural zones (Cohen & Biesman, 2021).

Evidence-Based Insights on Longevity and Integration

  • High G′ fillers in deeper areas withstand mechanical forces and enzymatic degradation, offering extended durability (Trévidic et al., 2023; Park et al., 2021).

  • Histologic studies show low-viscosity, low-cohesivity fillers integrate smoothly into tissue, reducing the risk of nodules (Flynn et al., 2012; Sundaram et al., 2015).

  • Longitudinal studies confirm that deep-placed high G′ fillers (chin, mid-face) maintain lift significantly longer than those placed in more mobile areas (Park et al., 2021).

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Final Takeaways

Choosing the right filler based on rheologic evidence—elastic modulus, cohesivity, and viscosity—is essential for achieving structural integrity, natural outcomes, and longevity. With products ranging from CaHA to HA formulations like Revanesse Versa, injectors can customize treatments for each facial area according to scholarly validated principles.

References (APA Style)

Choi, M. S. (2020). Basic rheology of dermal filler. Archives of Plastic Surgery, 47(4), 301–304. https://doi.org/10.5999/aps.2020.00731

Cohen, J. L., & Biesman, B. S. (2021). A review of Revanesse® Versa™: Rheologic characteristics and clinical use. Journal of Cosmetic Dermatology, 20(3), 784–790.

Flynn, T. C., Carruthers, A., & Arkins, J. (2012). Histologic evaluation of various tissue-incorporated dermal fillers. Dermatologic Surgery, 38(11), 1879–1889. https://doi.org/10.1111/j.1524-4725.2012.02554.x

McCarthy, A. D., Soares, D. J., & Chandawarkar, A. (2024). Comparative rheology of hyaluronic acid fillers. PRS Global Open, 12(8), e6068.

Park, S. H., Kim, J. Y., & Lee, S. H. (2021). Rheologic properties and longevity of HA fillers in different facial planes. Aesthetic Surgery Journal, 41(5), NP547–NP557.

Sundaram, H., Voigts, R. A., & Beer, K. (2015). Basics of dermal filler rheology. Dermatologic Surgery, 41(Suppl 1), S1–S9. https://doi.org/10.1097/DSS.0000000000000304

Trévidic, P. L., Vallières, J. L., & Lecomte, P. (2023). Injectable filler properties and tissue response: a review. RSC Advances, 13(27), 18045–18060. https://doi.org/10.1039/D3RA04321E

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